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Current transport infrastructure in Europe depends on numerous steel and concrete-steel bridges, often from high-strength steel. One of the main engineering challenges related to such bridges is to ensure their reliability during their whole lifespan. It is not easy as load by automotive or rail transport typically induces fatigue effects, especially on steel parts. It is usually necessary to execute periodic inspections which should make possible timely detection of issues (cracks) which would make effective repairs possible. Thus, it is important to be able to plan these inspections in right times and to inspect the critical details with focusing on their fatigue damage. The paper discusses some challenges related to this approach. The Direct Optimized Probabilistic Computation method (DOProC) is combined with linear fracture mechanics analytical solution to find the time of the first inspection. Then it is assumed that modified solution can be used to find times of further inspections. In the paper there are discussed issues related to the speed of the DOProC in such application and the approaches to limit the computational time without a loss of precision. [ABSTRACT FROM AUTHOR]

In the construction of steel structures and especially bridges, the use of high-strength steel (HSS) has been increasing in recent decades. The use of steel with a higher yield strength allows the design of slimmer as well as more aesthetic constructions. Design often leads to cost and material savings. In cases where the ultimate limit state of the structure is not a decisive factor of the design (but on the contrary the serviceability limit state, dynamic behavior of the structure, stability or fatigue of the material), the advantage of HSS becomes questionable. In such cases, the resulting resistance of the HSS structure is affected mainly by fatigue resistance. The article is focused on the initial study of fatigue damage prediction of HSS structures using linear fracture mechanics and probabilistic approach. [ABSTRACT FROM AUTHOR]

Corrosion is a very complex problem, which is affected by many factors. Corrosion generally produces serious changes in the surface morphology and corrosion pits that develop on the structure surface can interact with other defect such as cracks. In this paper, the influence of a corrosion pit on fatigue propagation of a perpendicular crack in a bar subjected to tensile loading is analyzed. Particularly, the effect of various corrosion pit sizes and distances from the crack on basic fracture parameters is investigated. A numerical model of the described specimen with a crack and a corrosion pit close to each other has been created and finite element calculations have been performed in order to obtain dependences of stress intensity factor ranges and T-stress on the crack length. The plots obtained enable to formulate conclusions on crack behavior near a corrosion pit. It was found out that some configurations could lead to slower fatigue crack propagation and could slightly weaken the dominant mode I of loading. [ABSTRACT FROM AUTHOR]

The paper deals with time dependent probability analysis of the failure of a steel bridge. The theoretical model of fatigue crack propagation is based on linear fracture mechanics. The statistical Monte Carlo method is applied to the analysis of failure probability. The results of probability analysis are elaborated applying the calibration curves processed, based on experimental research. Some aspects of the random sampling methods are discussed. [ABSTRACT FROM AUTHOR]

The article is focused on the exploration of fatigue damage to bridges and steel structures subjected to cyclic loading. Computational model is focused on fatigue crack propagating from the surface and it is based on linear elastic fracture mechanics utilizing the Paris-Erdogan's law. The behavior of the carrier element susceptible to fatigue damage is experimentally investigated on specimens with various types of load and it is expressed by a calibration function. For the prediction of fatigue damage over time, calibration functions for short edge cracks were derived based on the results of the experiment, and the acceptable size of the fatigue crack in damaged structural component under analysis was determined. Using the derived relationships, a stochastic analysis of the selected element was performed and the results are discussed. [ABSTRACT FROM AUTHOR]